POIYZOA. 101 



74. C. aculeata, Hassall; Johnston, I.e., p. 285. Cells cylindrical, 

 bent, with scattered pores, and with a long spine on the outer side ; 

 orifice free ; ovicell pear-shaped, dotted. 



Lyall's Bay. Europe. 

 Parasitic on seaweed. 



MARGARETTA. 



Cells disposed in four rows, back to back, each pair facing at right 

 angles to those above and below ; furnished with long bristles. 

 Cape of Good Hope. 



75. Mi. foarfoata, Lamark, Anim. sans vert., ii., p. 178 ; _3 

 cereoides, Gray, Dieff". N.Z., ii., p. 293, nee Cellaria cereoides, Ellis. 

 Cells immersed, the mouth only projecting, surface granulated ; mouth 

 not thickened ; a long bristle on each side of the mouth. White or 

 pale brown. In time the bristles fall off, but their position can always 

 be recognized by a cup-shaped depression. 



Lyall's Bay. Cape of Good Hope. 



FAMILY IDMONEID^. 



Polyzoarium erect, simple or branched ; branches continuous, 

 cylindrical or sub-compressed, free or anastomosing. 



HORNERA. 



Polyzoarium ramose ; branches dichotomous and free, or united by 

 short transverse raniules, so as to constitute a retiform expansion ; 

 cells opening on one side only of the branches, which surface is marked 

 with wavy anastomosing ridges, in the more or less rhomboidal inter- 

 stices of which the openings of the cells are situated. 



Europe. Kamtschatka. India. Patagonia. Australia. 



76. H. gOllldiana, Buslc, Crag Polyzoa, p. 95. Foliaceous, in- 

 fundibuliform, waved, reticulated ; mouths of the cells sub-orbicular, 

 with a slightly raised and thickened margin ; interspaces coarsely 

 granulated ; back finely granulated and lightly striated ; fenestrse 

 small ; branches cylindrical. White. 



Chatham Islands only. Australia(P). 



I refer this species to H. gouldiana, Busk, in order to prevent an 

 unnecessary multiplication of names, but 1 have seen no sufficient 

 description of that species. 



77. H. S(juamosa, sp. nov. Foliaceous, waved, infundibuliform, 

 reticulated ; mouths of the cells sub-orbicular, with a raised and 

 scarcely thickened margin ; interspaces finely granulated and with 

 slightly raised, scaly, longitudinal lines ; back finely granulated, with 

 slightly raised, rather scaly lines ; fenestrse small ; branches com- 

 pressed. White or pale brown. 



Chatham Islands only. 



The cells are more distant than in the last. 



78. H. Striata, Milne-Edwards; Stoliczka, Voy. Novara, Polos., 

 p. 107. Polyzoarium cespitose ; branches cylindrical, not reticulated ; 

 mouths of cells disposed more or less regularly in longitudinal series, 



